dont drink anything "diet" that actually makes things worse. if your going to drink something sugary, drink something made with REAL sugar, like pure cane sugar, or stevia extract, that actally helps your body metabalize it. avoid high fructosie corn syrp!

Good to know

Was first gonna say "try watching what you eat and try exercise more" before I saw that you already said it.
I want to say, try not to eat too much, but also don't try eating too less and try to exercise at least once a day (depending on what type of exercise we're talking about), but I honestly don't know much about stuff like this, and I happen to be trying to lose some weight as well.

Diet:
I use an app called "Fat secrets" were I document absouletly everything I eat.
It gives you tons of statistics about calories and nutrients and you can easily see which foods are wrong and when you did mistakes.
Hopefully fixing it in the coming days and weeks

Excersize;
Screw cardio, start doing resistance training and build some muscles. Even if it's just a baseline musclemass that is not visible. Losing weight always comes with your body trying to do everything to safe energy. And it does it by breaking down your muscles and thereby reducing your daily calory need. If you workout 3 times a week and eat protein rich, your body cannot do it. You maintains a healthy need of calories and you burn passively.

Alrighty I think it might be a slight typo in your response, do you mean "If you work out three times a week and eat protein rich, your body can do it."?

I might have phrased it wrongly... I meant if you do training, your body can't start breaking down your muscle mass D:

Gotcha. Thanks for your advice.